Choosing Huoditang teaching experimental forestry station as the study object, which located in Qinling Mountain, the pristine forest landscape pattern of this area is studied, and the general trend of biomass per unit area changing with the environmental elements gradients is also analyzed. In this study many data are used such as the aerial photographs taken in the 1950s, the forest phase maps and the forest management information through detailed investigation. The principle of the four order...